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I (and others) have made this comment several times, but now I'm posting it as a formal feature-change request. Please consider replacing the "PRO" badge with something more abstract. A little picture of Robot came to mind as one possibility, if gold stars aren't adequate.
The "PRO" word itself seems to be pretty divisive, with many of the users who can't or won't pay taking offense. They seem to think that the paid users themselves are to blame for "lording it over" everyone else. This is obviously detrimental to the whole community here.

Thanks, Kelsey.
Even though I was biding my time before "Going Pro," to see if the Pro badge would be changed in accordance with popuplar demand, it didn't occur to me to make a formal request. But now that you have made it, I hereby formally second your request (or at least add my voice to the clamor for change).
I, too, think a little icon of the instructables Robot would be ideal. It wouldn't carry the connotations of superiority that "PRO" does or gold stars would, and it might tend to inspire curiousity that would lead people to the "Sign up to support us" page.
It would mean that the "Go Pro" slogan would not longer apply, and we'd have to come up with a new one... Perhaps something like "Got Bot?" :)